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-rw-r--r--14-Longest-Collatz-Sequence/collatz.c31
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diff --git a/14-Longest-Collatz-Sequence/collatz.c b/14-Longest-Collatz-Sequence/collatz.c
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+++ b/14-Longest-Collatz-Sequence/collatz.c
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+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+// In C, it's immediately obvious my python solution is inefficient
+
+// For keeping track of the length of sequences
+// c is a temporary counter, s changes when c reaches a new maximum
+long int c = 0;
+long int s = 0;
+long int collatz(long int seed){
+ c++;
+ if(seed == 1)
+ return 0;
+ if(seed % 2 == 0)
+ seed = seed / 2;
+ else
+ seed = 3 * seed + 1;
+ collatz(seed);
+}
+
+int main(){
+ for(long int i = 1; i < pow(10, 6); i++){
+ c = 0;
+ collatz(i);
+ if(c > s){
+ s = c;
+ }
+ }
+ printf("The longest sequence has %d numbers \n", s);
+ return 0;
+}